Navigating the Challenge:

Along with an ageing water network, Wellington Water have the ever-present risk of seismic activity to consider. Mitigating the risk of water disruption is front of mind as Wellington Water develop and roll out a sustainable strategic plan, including seismic resilient pipelines.

Wellington Water resolved to improve the flexibility of a critical DN900 bulk water steel main situated along the Esplanade in Petone. The pipeline connections on either side of a valve chamber presented an increased risk of failure in the aftermath of an earthquake event.

Forging a Resilient Path

United under the Hynds Group - Hynds Pipes, Hynds Water, and Hygrade Water collaborated seamlessly with Wellington Water to orchestrate a dual-pronged solution: Seismic Resilient Ductile Iron pipe (SRDiP) in conjunction with Flex-Tend® Flexible Expansion Joint connections.

The Wellington Water Bulk Water Team subsequently installed two substantial Flex-Tend® joints either side of the valve chamber, each weighing 4.5 tonnes. The operation was supported by a custom-built cradle to help steady the devices as they were positioned in place.

In an area considered at higher risk of liquefaction along the shoreline, the ripple effect of this intervention to the security of the city water supply is significant.